A microbial fuel cell (MFC) produces electricity using metabolic energy of bacteria, and all organic materials including waste may be fed by bacteria and thereby used to power of a fuel cell. The MFC that has been attracting attention as an alternative energy technology is a high efficiency energy conversion device which may use energy of pollutants in wastewater as fuel while removing the pollutants as food of microorganism, and directly recover electricity from the pollutants. Thus, when the MFC is used in wastewater treatment, clean energy may be provided, and effective treatment of wastewater may be possible.
FIG. 1 shows a basic operation process of a conventional MFC. Many elements are needed in order to produce an MFC, but three systems are basically needed. First, an anode for extracting electrons generated in a cell is needed. Second, a cathode for reducing the extracted electrons is needed. Third, an ion exchange membrane for separating the above-described two electrodes is needed. An existing MFC is operated in such a manner that the anode and the cathode are separated using an artificially produced thin film, electrons are extracted from a grouped cell in the anode, and oxygen supplied from the outside is reduced by the electrons in the cathode.
In many research institutions, research has been recently conducted into commercialization of the MFC. However, the biggest obstacle to the commercialization may be low energy density due to low efficiency.